<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    *{
        margin:0;
        padding: 0;
    }
    /* 让容器的宽度和高度都充满全屏 */
    html,body{
        width: 100%;
        height: 100%;
    }
    body{
        background-color: pink;
        display: flex;
        flex-direction: row;
        justify-content: center;
        align-items: center;
    }
    .heart{
        width: 200px;
        height: 200px;
        background-color: red;
        position: relative;
        transform: rotate(45deg);
        animation: heartbit 1s alternate infinite;
        box-shadow: 0 0 30px red;
    }
    .heart::before{
        content: "";
        width: 200px;
        height: 100px;
        background-color: red;
        position:absolute;
        left: 0;
        top:-99px;
        border-radius: 100px 100px 0 0;
        box-shadow: 0 0 30px red;
    }
    .heart::after{
        content: "";
        width: 100px;
        height: 200px;
        background-color: red;
        position:absolute;
        left: -99px;
        top:0;
        border-radius: 100px 0 0 100px;
        box-shadow: 0 0 30px red;
    }
    @keyframes heartbit{
        0%{
            transform: rotate(45deg) scale(0.6);
        }
        100%{
            transform: rotate(45deg) scale(1.4);
        }
    }
</style>
<body>
    <div class="heart"></div>
</body>
</html>